[MartyTX]

I’m thinking about adding a tablet to my electronic gadget lineup. I already have a desktop, laptop, iPhone and Nook ST.

The 1st generation iPad at Walmart for $200 net on Black Friday seems too good to pass up, but I’ve read several reviews about its low resolution. I’ve also read that Pixels Per Inch (PPI) is a better determinant of screen clarity than just resolution. 800x600 looks fine on my 6” Nook, but not so fine on a 21” monitor.

So, I did some browsing and some messing around with Excel, and made a worksheet that easily calculates Pixels Per Inch.

To use the worksheet you have to enter the screen resolution (pixels) and the screen diagonal (inches) into the GREEN cells. This info seems to be given in most advertisements. All the other cells are filled by the formulas. I’ve populated the sheet with the devices that I already own and some I’m thinking about. Simply erase the GREEN cells and enter your own data.

NOTE: Some devices can be read in portrait and landscape mode. For consistency, I listed the larger number first for all devices. For example, even thought the Nook is read in portrait mode 600w x 800h (3:4), I’ve listed it as 800x600 (4:3). Regardless of which number you call the width and which you call the height, as long as you enter both dimensions the PPI stays the same.

Hope some Excel users will find this sheet useful.

Marty